Genetic, biochemical, and biophysical analysis of the metabolic regulatory enzyme, L-threonine deaminase from Salmonella typhimurium is being studied in order to describe the mechanism whereby small molecular weight compounds modulate enzyme activity. An amibivalent role of this enzyme in genetic regulation of the ilv gene cluster will be studied by using genetic analysis and by in vitro analysis of gene expression. BIBLIOGRAPHIC REFERENCE: Hofler, John G., and Burns, R. O. Differentiation of the activator and active sites of biosynthetic L-threonine deaminase. Federation proceedings, 1977.